MELBOURNE, Australia (AP) Mackenzie McDonald knew he was ready to turn pro after his junior year at UCLA. He had just won the NCAA singles and doubles titles and believed he was ready to take the next step.
After his surprise showing at this year's Australian Open, he certainly made the right decision.
The 22-year-old McDonald emerged from qualifying to give a scare to No. 3-ranked Grigor Dimitrov in the second round of the Australian Open on Wednesday night, taking the Bulgarian to the distance at Rod Laver Arena before eventually falling 4-6, 6-2, 6-4, 0-6, 8-6 in nearly 3+ hours.
''I was soaking it all in,'' McDonald said. ''It was a long match and I enjoyed every single moment of it.''
McDonald, who entered the tournament ranked No. 186, failed to get through qualifying at the majors three times last year, but his luck changed at this year's Australian Open where he defeated French journeyman Stephane Robert in three sets in the last qualifying round to claim a spot in the main draw.
McDonald then beat fellow qualifier Elias Ymer of Sweden in the first round - his first win anywhere at the elite tour level. It was the boost he needed after struggling on the lower-tier pro circuits following his decision to leave college in 2016.
''Especially when you're starting out, you have doubts,'' he said after his first-round match. ''You feel like some times are really rough, especially like when you lose early at a Future or Challenger (tournament). . You just have to stay really level-headed with this sport.''
Going into the second-round match against Dimitrov, McDonald was the heavy underdog. The highest-ranked opponent he had ever faced was No. 69 Rajeev Ram in Newport in 2016.
But instead of being overawed by the situation, McDonald broke ATP Finals champion Dimitrov's serve to capture the first set and then hung in when the more experienced Bulgarian stormed back to claim the next two.
McDonald appeared to be thoroughly enjoying himself as he took the fourth set 6-0 and extended the match deep into the fifth, pumping his fists after winners and repeatedly waving his arms over his head to rally the crowd to his side.
''I know how close I was to winning,'' McDonald said afterward. ''But he's a good player. He's been out here a while. I'd overall say there's so many more positives than negatives.''
Fellow American Sam Querrey knows McDonald well, having spent time with him in California, and he's not surprised by his rapid improvement in the last couple years.
''Even when he was in college, he was a freshman, a couple times I'd give him a ride home after practice and he'd ask me questions the entire car ride home, like, `What do you do on your forehand here?,' `What's the travel like?''' Querrey said. ''He was just like always super inquisitive, so I'm glad to see it's paying off.''
McDonald has also practiced with Dimitrov, and spent time hitting with Roger Federer. His success also shows there's a path for tennis players who decide to go to university instead of turning pro in their teenage years.
''I went to college and I didn't really have as many opportunities to play as many ATPs as some of these other guys,'' he said. ''Once you go (pro), you have to give it your all. That's what I feel I've been doing since I stepped foot out of UCLA.''
